Welding Activities: Is EBC a Reliable Indicator for Assessing Metal Exposure or Early Biological Effects? A Systematic Review

Welding processes generate complex aerosols containing fine and ultrafine particulate matter, metal fumes, and gaseous by-products that may pose significant respiratory risks for exposed workers. Exhaled breath condensate (EBC) has emerged as a promising non-invasive matrix for human biomonitoring, offering the opportunity to assess exposure directly at the pulmonary target site and to evaluate early biological responses. This study systematically reviewed the scientific literature available in PubMed, Scopus, and ISI Web of Science to examine the role of EBC in exposure and effect biomonitoring among welders. Sixteen studies met the inclusion criteria. Overall, the evidence indicates that EBC is a suitable matrix for assessing occupational exposure in welding activities. Several studies reported increased concentrations of metals-including manganese, nickel, iron, and chromium in welders compared with unexposed controls, as well as higher post‑shift levels compared with pre‑shift samples across the workweek. Associations between cumulative exposure to inhalable dust and metal concentrations in EBC were also observed, even at low exposure levels. EBC has additionally shown potential for detecting early-effect biomarkers, such as indicators of oxidative stress, lipid peroxidation, protein and nucleic acid oxidation, and inflammatory mediators. These findings provide insight into biochemical alterations occurring in the airway lining fluid of welders. Despite encouraging findings, key methodological issues persist. The lack of standardized protocols for EBC collection, storage, and analysis hampers comparability across studies. Indeed, further research should elucidate EBC production and dilution kinetics and clarify metal toxicokinetics to fully establish EBC as a reliable biomonitoring matrix for occupational health research and practice.